Projection machine



Jan. 1, 1946. w. L. CHAMBERS PROJECTION MACHINE Filed Feb. '4, 1942 4 Sheets-Sheet l Jan. 1,1946. w. L. CHAMBERS PROJECTION MACHINE Filed Feb. 4, 1942 4 Sheets-Sheet 2 ilk $606725? 99 Zdorzfgf M68715 .Fan. 1, 1946. w 1 CHAMBERS 2,391,879

PROJECTION MACHINE Filed Feb. 4, 1942 4 Sheets-Sheet 3 -59 gm w- Patented Jan. 1, 1946 UNITED STATES PATENT OFFICE PROJECTION MACHINE Worthy L. Chambers, Chicago, 111., assignmto Novex Corporation, Chicago, 111., a corporation of Illinois Application February 4, 1942, Serial No. 429,534

9 Claims.

tioned as in Fig. 1, and with the base structure partly broken away and shown in section to re-- veal the motor and drive connections therefrom.

Fig. '5 is a top plan view with the parts positioned as in Fig. 1.

Fig. 6 is a vertical sectional view of the projector unit taken on a larger scale than the preprojection machine having a self-contained projection screen and a movably mounted projector including a lamp, 2. lens system, and a slide-receiving space, and adjustable either to project an image onto said screen or onto a distant screen separate from the machine. I

Another object of the invention is'to provide a projection machine in. which the projector itself is tiltably mounted upon a hollow base structure containing a mirror and a translucent projection screen so arranged that an image may be projected onto the mirror and reflected onto said screen, or the projector may be adjusted to throw the image past the mirror onto a screen separate from the machine.

ceding views, being taken as indicated at line 6-6 on Fig. 5. 1

Fig. 7 is a section taken substantially as indicated at line 1-1 of Fig. 6. but with some parts broken away. a

Fig. 8 is a fragmentary rear elevation of the endless belt and its slide holding frames.

Fig. 9 is a detail plan section of the slide guidv ing frame and feed mechanism, taken as indicated at line 9-9 on Fig. '7.

Fig. 10 is a detail face view of the condenser lens and the supporting frame therefor.

A further object of the invention is to provide a projection machine with an endless belt composed of slide carriers adapted to removably support a'plurality of individual, translucent slides adapted for projection in the machine, together with a track or guide supporting such belt and means for advancing the belt intermittently for successive display of the slides.

And it is also an object of the invention to provide a projection machine with an endless belt of slide carriers, each adapted to removably support a transparent slide, together with automatic, motor driven means for advancing the belt intermittently to bring the slides successively into registration with the light source and lens system of the projector.

Other objects and advantages of the invention will appear from the following description taken in conjunction with the drawings, in which:

Fig. 1 is a side elevation of the projection machine embodying this invention, showing the projector unit tilted to horizontal position for throwing an image onto a screen separate from the machine.

Fig. 2 is a side elevation of the projector with the supporting housing and base structure shown in section and with the projector tilted downwardly for cooperation with the mirror and projection screen carried by said housing.

Fig. 3 is a rear elevation of the machine with the parts positioned as shown in Fig. 1, and with I a portion of the base broken away.

Fig. 4 is a front elevation with the parts posi- While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the invention, and that the same is not limited to the particular form herein shown and described, except in so far as indicated by the appended claims.

As illustrated in the drawings, the projection machine embodied in this invention may be considered as comprising three principal units, namely, the projector unit proper shown at i in Fig. 1, the supporting housing 2 on which the unit I is tiltably mounted by means of pivots 3,

and finally the base 4 which contains the driving motor for the slide shifting mechanism. As seen in Fig. 2, the projector unit I may be tilted about its pivotal mounting at 3 so as to direct its focused beam onto a mirror 5 which is supported within the housing 2 at such an angle as to reflect the image onto a translucent screen 6, which may be of ground glass" or like material. This viewing screen 6 is considerably larger than the transparency which is introduced into the projector in the form of a so-calledfslide and which may bear either a picture or a printed message. And it may be understood that although the machine includes an electric motor I disposed in the base 4 and is designed for the automatic shifting of a plurality of slides through the projector for their successive display, the housing 2 and the projector unit I mayv be removed from the base section I and may be employed independently of the automatic drive,'

space provided for them in the projection unit I. Whether the automatic motor driven shifting means is employed or not, the projection unit I may be tilted from its inclined position, shown in Fig. 2, to a substantially horizontal position, as shown in Fig. 1, for throwing the image onto a larger screen at a considerable distance from the projection machine when desired. Thus, in connection with sales work, the machine may be set on a desk or table, and can be operated by the salesman for displaying attractive pictures of his line of goods, and the'projected enlargements of the pictures may be viewed by the prospect either at the translucent screen 6, or on any convenient area, such as the wall of his ofllce, at a short distance away from the projector.

The projection unit I, as shown in detail 'in Fig. 6, includes a lamp housing 8 in which a suitable electric lamp bulb, indicated at 6, is mounted in position between a reflector III and a condenser lens assembly consisting of two lenses II and I2 supported in a special frame which is shown in Fig. 10. The frame is rectangularin form and consists of two similar parts I3, I3.

which are held together by'spring clips I4, I4 and which, when assembled, form a circular opening I5 coaxial with the lenses II and I2. The lenses are supported in notched lugs I6 which project from the front and rear faces of. the members [3, I3 and engage the edges of the lenses. Preferably the margin of the circular opening I6 is grooved to secure a tinted, transparent screen H in this opening, which serves to eliminate most of the heat rays from the light and thus to protect the transparencies which are to be projected. .The projector unit I is a twopart shell, preferably of molded plastic material, with the two parts held together transversely by tie rods I8, and the side walls of this shell are provided with channels to engage the edges of the condenser support I3, I3. A bowed spring element I9 snapped into position between the side walls of the shell serves to hold the support in the channels, as shown in Fig; 6.

A suitable lens or lenses, not shown-in detail but referred to as the "focusing lens, may be supported in a tube 26 which is slidably carried in a sleeve 2| fixed in the front wall 22 of the projector shell I. For focusing the image, the tube 26 is shifted axially in the sleeve 2I by Y manipulation of a knob 23 carried at one side of the shell I. with its stem or shank 24 extending into the shell through an arcuate slot 26. The stem 24 is engaged in the upper end of a lever 26 fulcrumed at 21 and connected at its lower end to the inner end of the lens tube 26. Preferably,-thislever is formed in duplicate, as indicated in Fig. 7, with its two arms transversely connected by a portion 23 making the lever-approximately of inverted U-shape, with its two portions 26 provided with separate fulcrum pins 21 engaging the side walls of the unit I. In addition, a second yoke or lever is fulcrumed on the pins 21, with its duplicate members 29 extending upwardly therefrom and connected by a transverse portion 36 just above the part 26 of the lever 26. The shank 24 of the lcnob23 is journaled in one of the lever arms 29 and the terminal portion of this shank is an offset crank 3| which enga es one of the lever members 26. Thus the rotation of the knob 23 rotates the crank 3| to produce limited movement of the lower ends of the levers 26 about the fulcrum pins 21, but bodily movement of the shank 24 through the arcuate slot 26 swings the two levers 26 and 26 together to eifect a greater range of movement of the lens tube 26. The inner end of the tube is' formed with slots 32 and the lower ends of the lever members 26 are provided with pins 33 engaging said slots. To bring the image into focus on the screen, the operator shifts the knob 23 bodily through the slot 26 to the approximately correct position and then rotates the knob for the final adjustment to secure a perfect focus.

Between the condenser lenses II, I2 and the focusing lens carried intube 26, there is secured in the shell of the projector unit I a transverse partition or bulk head 34 which registers with slots 36 in the side walls, and which includes a rectangular opening 3,6 substantially centered with respect to the condenser and focusing lenses. At the upper and lower edges of this opening 36, the partition 34 is formed with horizontal shoulders 31 and 38 between which a transparent slide may be inserted, or a suitable slide holder may be secured for guiding the slides through the slidereceiving opening formed by the slots 36 and shoulders 31 and 38.

In the structure as illustrated, a guide frame 46 formed of sheet metal is secured in the slots 36 and extends through the unit I from side to and 43 adjacent the edges of this opening U.

The lower channel 43 is slotted at the bottom for communication with the secondary channel 44 below it, whichserves to guide a reciprocating bar 46 carrying a yieldable tooth or dog 46 in position to travel through the channel 43.

A flexible belt 66, preferably of thin sheet metal, extends through the channels 42 and 43. This belt includes apertures 6I at regular intervals, and registered with each aperture there is secured to the face of the belt a slide holder 62 comprising a sheet metal frame having an aperture 63 substantially registering with the aperture 6| of the belt, and having its upper and lower edges turned over to form channels 64 and 65. Each slide holder 52 is secured to the belt 56 by spot-welding, or by other convenient means, which engages only the middle portion of the holder with a limited area of the belt so as not materially to impair the flexibility of the latter, and the ends of the belt are joined together as by the hinge connection shown at 66. A curved track for the belt 66 is shown at 61 in Fig. 5, with opposite ends of the track connected in any suitable manner with the ends of the guide frame 40 at opposite sides of the projector shell I, so that the track extends around the rear end of the shell and provides a continuous circuit in which the belt is slidably movable. At intervals corresponding to the spacing of the openings 6|, the belt is provided with driving lugs or teeth for engagement by the yielding dog 46 of the bar 46, and, as a matter of convenience, these lugs are formed on the rear faces of the slidev holders or frames, as shown at 66, and the belt 66 itself has clearance notches 69 through which these lugs project for engagement by the driving tooth 46. Thus the movement of the bar 46 in one direction shifts the belt 66 by a measured distance sufficient to move one of the slide holders 62 out of registration with the opening 36 in the partition 34 and to bring the next slide holder into such registration for projection of a transparent slidecanied by it. Each slide may consist of a pair of cover glasses with a transparent film between them, or of suitable pastcboard panels between which a film is similarly held, and in either case the slide is dimensioned to fit into the channels 54 and 55 of the holder 52 and to be frictionally held therein with its picture area registered in the aperture 53 of the holder 52. Such a slide is shown at 60 in Fig. 4 with its picture area indicated at 6|.

The automatic actuation of the slide-shifting bar 45 is accomplished by means of the electric motor 1 supported in the base 4 and shown as combined with a housing 65 which encloses any suitable speed reduction gearing. The slow speed shaft 66 extends from the housing 85 and carries a crank disk 61 having a crank pin 68 which engages in a longitudinal slot 69 of a link Ill. The link is connected to the lower end of a lever ll fulcrumed at 12 on a support secured to the base 4 and the upper end of the lever is reduced at 13 to engage loosely in an opening 14 in the end portion 15 of the slide bar 45. Thus, the ratation of the crank disk 61 actuates the link 10 and oscillates the lever II to reciprocate the bar 45. By virtue of the slot 69, the movement of the link 10 is rendered intermittent, being delayed while the crank pin travels the length of the slot twice in each revolution of the disk 61. With the arrangement shown, the active movement of the bar 45 for shifting the slide holders is accomplished as the crank pin 68 is traveling through the lower portion of its curved path, as seen in Fig. 4; then as the crank passes the horizontal diameter of the disk 61 it rides through the slot 69 until it strikes the opposite end of the slot. Thereafter the crank pin drives the link 10 in a direction to cause the return or idle stroke of the bar 45 and again traverses the lot 69 before commencing the active stroke of said bar. Thus, the provision of the slot 69 prolongs the interval through which the belt 50 and the slide holder 52 remain stationary for display of the slide which is registered with the lens system and light source of the projector; but with each'revolution of the crank disk 61 the bar 45 is given a full reciprocation and the next succeeding slide on the belt 50 is presented and displayed.

Preferably, to preserve a neat appearance, the track 51 is provided with a-cover 'l'l fitting around the outer surface of the belt 50 as it is mounted in the track, and loosely enclosing the belt with sufilcient clearance for the several slide holders or frames 52 'as they stand in substantially tangential relation to the belt 53 when it traverses the curved portion of the track 51. This cover ll may be of sheet metal and sufilciently yielding to be easily removed so as to afford access to the belt and to the holders 52 to permit any one or more of the picture slides to be removed from the holders and replaced with other pictures to alter the display program.

In view of the tiltable mounting of the projector unit I on the hollow housing 2, the con- .iuctors 80 for the lamp 9 extend in channels in the side walls of the unit I, ending in flat annular terminals 82 which encircle the pivots 3, as seen in Fig. 6; and similar fiat annular terminals 84 are disposed in contact with the terminals 82 and are connected with lead wires 85 and 86, shown in Fig. 2, by which the current is supplied to the lamp 9. Thus, when the projector shell I is tilted about its pivotal mounting, the terminals 82 merely rotate against the terminals 84 without interruption of the circuit.

To insure satisfactory projection of the image onto the screen 6, the mirror is silvered on its outer surface, thus avoiding any double reflection; and the mirror is carried in a frame 90 having 9. lug 9 at its upper end engaged in an opening formed in a boss 92 which is cast on the inner surface of the housing 2, while the lower end of the frame 90 is provided with a brace arm 93 which may be slotted for engagement with a clamping screw 94, thus permitting the mirror to be adjusted accurately to the proper angle in the assembly process.

As seen in Figs. 1 and 6 the lamp housing has I a top wall formed with double louvres 95 which allow the escape of heated air without permitting the emission of light, and the back wall is made with single louvres which provide additional ventilation. The hollow base 4 rests on rubber buttons 4 which allow air to enter under the edges of the base, and an opening 4 in the top .wall of the base permits the air to circulate upwardly through the housing 2 and projection unit I.

The upward tilting range or unit I is limited by stop bosses 91 on its side walls which engage the upper edges of the housing 2, and in the downwardly tilted position the forward edge of the top wall of the unit I is stopped against the upper edge of the front wall of housing 2 as seen in Fig. 2. Friction springs fitted with felt or rubber pads 98 bear against the sides of the unit I to hold it at any position in its tilting range.

To insure accurate positioning of the slides I by the feed bar 45, the fulcrum 12 of lever II is carried on a pivotally mounted frame 99 adjustable by means of a screw I00, as shown in Figs. 4 and 5. The quiet operation of the belt 50 around its track 51 is aided by bearing strips of fabric, cord, or the like secured around the vertical wall of the track at 51- for contact with the belt 50 as indicated in Figure 6.

Preferably the housing 2 is .not attached to the base 4 but merely rests upon it with the rubber feet 2 engaged in suitably positioned holes in the top wall of the base as. indicated in Fig. 1. Thus, if it is desired to operate the projector manually without the aid of the motor I the housing 2 is simply lifted off the base 4 and the hole 14 becomes disengaged from the end 13 of lever II. The feed bar 45 may be actuated by.

hand, or the entire guide frame 40 and track 51 may be removed to permit individual slides or straight sets of views to be inserted in the slots 35 of the projector unit I.

I claim as my invention:

1. In combination with a projector which includes a lamp, a condenser lens, a focusing lens, and a housing in which said parts are mounted in operative relation and provided with a slide receiving slot, a hollow base on which said housing is tiltably carried with said slot above the base, a translucent screen disposed in a substantially vertical plane across one end of said base and a mirror in the opposite end positioned to directly receive an image projected by the focusing lens and to reflect such image directly onto the screen when the housing is tilted downwardy toward the mirror, said projector operating to project an image over and beyond said mirror onto a vertical surface when its housing is tilted to approximately horizontal position.

2. In combination with a projector which includes a lamp, a condenser lens, a iocusing lens, and a housing in which said parts are mounted in operative relation and provided with a slide receiving slot, a hollow base higher at one end than at the other end, means by which said housing is tiltably carried on said base with the slot exposed outside the base, a translucent substantiallyvertical screen across the higher end and an inclined mirror disposed opposite the screen at the lower end positioned to receive an image directly from the projector when its housing is tilted downwardly toward said mirror and to reflect such image directly onto said screen, the projector operating to project an image horizontally over and beyond said mirror onto a vertical surface when its housing is tilted to approximateiy horizontal position. I

3. In combination with a projector which includes'a lamp, a lens system comprising a condenser and a focusing lens, and a housing in which said parts are mounted in operative relation and provided with a slide receiving slot, a chamber with which the housing is swingably connected, a translucent screen disposed across one end of said chamber in a substantially vertical plane and a mirror in the opposite end positioned to directly receive an image projected by the focusing lens and to reflect such image directly onto the screen when the housing is swung with the axis of the lens system directed toward the mirror, said housing being adjustable at will into horizontal position to project an image past the mirror and onto a vertical surface outside the chamber. i

4. In a projector, a focusing lens, a tube in which it is mounted and a support for said tube ried by said belt, each holder comprising a frame with its ends open toward adjacent holders and with opposed channels extending longitudinally of the belt to engage opposite edges of a slide, said frame being attached to the belt at a limited area at the middle of the length of the frame, whereby each frame assumes a tangential relation to the belt in traversing a curve of said track and the open ends of its channels are exposed clear of the adjacent frames to facilitate removal or insertion of a slide.

7. In the combination defined in claim 6, said track comprising a channel having a fixed inner wall serving as the guiding means for the belt with flanges by and between which said slideholding frames are guided in their travel, and a removable cover disposed opposite said fixed inner wall in spaced relation thereto and completing the enclosure of the belt and slide holders, the removal of said cover from a curved portion of the track exposing the holders in position for inin which it is slidable in the direction of its axis. s

a housing by which the support is carried, and means for adjusting said tube comprising a lever fulcrumed on the housing with one end of said lever engaging the tube, a second lever fulcrumed coaxially with the first, an operating knob having a shaft rotatably mounted in the second lever with a crank arm on said shaft engaging the first lever whereby rotation of the knob actuates the crank to swing one lever relatively of the other and shift the tube through a limited distance and bodily arcuate movement of the knob with said levers actuates the levers together for shifting the tube through a greater range.

5. In a projector, a housing, lamp and supporting means therefor within the housing, a twopart condenser lens and a carrier therefor comprising a two-part panel having a circular opening and separable at asubstantially diametral line, each of said two parts having grooved lugs of limited circumferential extent upstanding from its opposite faces to engage the edges of the lenses respectively for supporting them in correctly spaced relation, spring wire clips holding the two parts of the panel together and guideways in the housing w'alls engaging opposite edges of the panel to position the panel therein.

6. In combination with a projector having a slide-receiving space, a curved fixed track disposed with its opposite ends adjoining said space at opposite sides thereof, an endless belt extending around-the track and through said space, a plurality of holders for transparent slides carsertion or removal of the slides. 1

8. The combination of a projector unit which includes a lamp, a condenser lens, a focusing lens, and a housing supporting said parts in operative relation and having a slide receiving space, with a base on which said unit is tiitsble on a horizontal pivot, a translucent screen supported on said base in a substantially vertical plane and reflecting means carried by the base, whereby'an image may be projected onto said screenin position to be viewed by a person facing said screen when the rojector is tilted to direct its beam of light downwardly toward said reflecting means, said unit being tiltable alternatively to a position in which its beam is directed horizontally and away from said screen for projecting a larger image onto a vertical surface at a greater distance from the unit where it may be viewed by the said person without substantially altering his own position.

9. A compact projecting apparatus comprising the combination of a projector unit which includes a lamp, a condenser lens, a focusing lens, and a housing supporting said parts in operative relation and having a slide receiving space, with a base on which said unit is pivotally mounted and including a translucent screen supported on said base in a substantially vertical plane and reflecting means carried by the base whereby an image may be projected onto said screen in position to be viewed by a person facing said screen when the said unit is swung to direct its beam of light toward said reflecting means, said unit being swingable alternatively upon its pivotal mounting to a position in which its beam is di- 

